Light Fixtures Comprising an Enclosure and a Heat Sink
Light fixtures including at least an enclosure, a heat sink, and a light-emitting diode. In one embodiment the heat sink has a first portion having fins (that protrudes outside of the enclosure) and a second portion to house and mount the LEDs (that is positioned within the enclosure). Certain embodiments also provide for gaskets and other structure to prevent leakage between the heat sink and the enclosure, such that the light fixture is water-resistant. Thus, embodiments of the light fixture may house LEDs and related electric components inside a water-resistant enclosure and cool those components by transferring thermal energy to the surrounding air.
The present subject matter relates generally to light fixtures, and more specifically, to the use of light emitting diodes in a light fixture having an enclosure and a heat sink.
BACKGROUNDAn important consideration in the design of light fixtures is selection of the light source. Fluorescent or incandescent lamps have long been the light source of choice in many light fixtures used in commercial applications. But fluorescent and incandescent lamps have drawbacks. For example, fluorescent lamps may result in undesirable lighting that is focused and intensely directed beneath the lamp but dark in areas peripheral to the lamp. Both fluorescent and incandescent lamps require a high level of energy, and thus, are more expensive to operate. Incandescent lamps burn out relatively quickly, which causes material waste. Fluorescent lamps contain mercury, a toxic substance. In general, fluorescent and incandescent lamps are not very “green” or environmentally friendly. Such lamps may also require increased operator time in changing out the lamp when it is burned out.
Another light source that is gaining in popularity is the light-emitting diode, or LED. LEDs might be desirable in certain applications because they generally require less power than fluorescent and incandescent lamps, and they also generate less waste. LEDs last longer, which may be desirable to users who operate the light fixture for long hours and could reduce the frequency of lamp replacements. Finally, LEDs do not contain any toxic mercury.
Despite the fact that it may not be desirable to use fluorescent or incandescent lamps, it may still be desirable to use at least part of the light fixture that was designed to house the fluorescent or incandescent lamp, as long as the special operating characteristics of LEDs are appropriately addressed. Manufacturing equipment and procedures that were used to make the existing enclosure can continue to be used to house the LED boards. Finally, re-using an existing enclosure preserves a consistent look in a room that may already be equipped with light fixtures. (Otherwise, the room may have some light fixtures with new enclosures and some with older ones that look different from one another.)
In general, it may be desirable to re-use at least some parts of a light fixture design (and in particular, an enclosure of a light fixture) to house an LED board or other light source. One problem arises, however, in managing the thermal energy that may be produced by LEDs. One way to manage thermal energy is to incorporate heat sinks into the light fixture. An existing fixture may not be provided with such heat sinks, however, and may not have room to incorporate such heat sinks. Managing the thermal energy may be particularly problematic if the enclosure of the light fixture is made of a material that is insulating, such as plastic, that traps the thermal energy inside the enclosure.
Another problem is that modifications to an existing enclosure may make the light fixture unsuitable for use in particular applications. For example, if the light fixture is to be used in an environment that may be exposed to water, such as a parking garage or other outdoor environment, then it may be desirable to provide a water-resistant light fixture. Modifying an existing enclosure may involve creating apertures in the enclosure, which may introduce water into the light fixture, damaging the components inside.
Thus, it is desirable to re-use parts of an existing light fixture, such as an enclosure, to house LED boards or other light sources.
It is also desirable to manage the thermal energy produced by such LEDs inside the enclosure, particularly if the enclosure is made of plastic.
Finally, if it is necessary to modify the design of an existing enclosure to house an LED board, then it may be desirable for such modifications to be water-resistant.
SUMMARYCertain embodiments of the invention provide for light fixtures comprising at least a heat sink and an enclosure to be used to house LED boards or other light sources. In one non-limiting embodiment, the heat sink includes a first portion having fins oriented outside of the enclosure and a second portion that extends into the enclosure and couples to an LED mount. The heat sink may be made of a thermally conductive material such that thermal energy is conducted away from the LEDs, into the heat sink, and out of the enclosure. Certain embodiments also provide for gaskets and other structure to prevent leakage between the heat sink and the enclosure, such that the light fixture is water-resistant. Thus, embodiments of the light fixture may house LEDs and related electric components inside a water-resistant enclosure and cool those components by transferring thermal energy (via conductive and/or convective cooling) away from the fixture.
Reference will now be made in detail to various and alternative exemplary embodiments and to the accompanying drawings, with like numerals representing substantially identical structural elements. Each example is provided by way of explanation, and not as a limitation. It will be apparent to those skilled in the art that modifications and variations can be made. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that this disclosure includes modifications and variations.
In some embodiments, the enclosure 12 may have been originally designed for use with a fluorescent or incandescent lamp. The enclosure 12 may be made of plastic such as a polycarbonate, or another material that is thermally insulating. Thus, certain embodiments described herein relate to the modification of enclosure 12 to be used with LEDs, or another light source that may require a heat sink to conduct thermal energy.
One such modification includes coupling of a heat sink 30 with the enclosure 12.
The heat sink 30 has an overall length L2. In the embodiment shown in
As shown in
The heat sink 30 be made of a thermally conductive material, such as metal, including aluminum, steel, copper, or metal alloys to conduct heat away from the LED board 76. Additionally, and as shown in
Electric components 62 used in powering and operating the fixture 10 may be housed in the space defined between the two sidewalls 34. For example, the cross-sectional views of
As shown in
As shown in
Finally, mounting brackets 100 may be provided to couple to cut-outs 46 defined in the heat sink 30. The mounting brackets 100 may be used to mount the fixture 10 to a ceiling or other structure. Any number of mounting brackets 100 may be provided.
The respective components of the light fixture 10 may be made of a variety of materials. For example, in certain embodiments the enclosure 12 is made of plastic such as a polycarbonate. In other embodiments the enclosure 12 may be made of other materials, such as metal. If desired, the enclosure 12 (both top and bottom portions 14, 16) may be made using a mold. Additionally, in certain embodiments the heat sink 30, channel 50, side bracket 60, mounting panel 70, transition piece 80, and mounting brackets 100 (and any end pieces or plates associated with these components) be made of a thermally conductive material, such as metal, including aluminum, steel, copper, or metal alloys. Some or all of these components may be made with an extrusion manufacturing process. Alternatively, some or all of these components may be made by stamping and folding (for example, stamping the shape of transition piece 80 and then folding it). One of skill in the art would realize that substitutions may be made to either the choice of materials or the manufacturing technique for any of the components of fixture 10. For example, the heat sink 30 may be made of some other non-metallic conductive material, and may be made with a mold in some embodiments.
While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude inclusion of such modifications, variations and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art.
Claims
1. A light fixture comprising:
- an enclosure comprising a top portion coupled to a bottom portion, wherein the top portion defines an aperture;
- at least one mounting panel positioned within the enclosure;
- at least one light emitting diode mounted on the mounting panel; and
- a heat sink comprising a first portion positioned within the enclosure via the aperture and a second portion comprising a plurality of fins and positioned exterior to the enclosure, wherein the heat sink is coupled to the at least one mounting panel to conduct heat generated by the at least one light emitting diode away from the at least one light emitting diode and out of the enclosure.
2. A light fixture as in claim 1, further comprising a gasket coupled between the heat sink and the aperture of the enclosure.
3. A light fixture as in claim 1, further comprising a thermal interface material coupled between the mounting panel and the at least one light emitting diode.
4. A light fixture as in claim 1, further comprising at least one mounting bracket coupled to the heat sink for mounting the light fixture to a surface.
5. A light fixture as in claim 1, further comprising a channel positioned within the enclosure and coupled to an end of the heat sink, and an electric component coupled within the channel.
6. A light fixture as in claim 1, further comprising a side bracket positioned within the enclosure and coupled to the first portion of the heat sink, and an electric component coupled between the side bracket and the first portion of the heat sink.
7. A light fixture as in claim 1, further comprising a transition piece coupled to an end of the heat sink and the top portion of the enclosure.
8. A light fixture as in claim 1, wherein the heat sink is a single integral piece.
9. A light fixture comprising:
- an enclosure comprising a top portion that defines a cavity and a cut-out for providing access to the cavity;
- a heat sink comprising an upper surface, at least one set of fins extending from the upper surface, and two sidewalls extending downwardly from the at least one set of fins, wherein the heat sink is coupled to the enclosure such that the set of fins are positioned exterior to the enclosure and at least a portion of the sidewalls are positioned within the cavity of the enclosure;
- a light source assembly coupled to at least one sidewall, wherein the light source assembly comprises a mounting panel and at least one light emitting diode, wherein the heat sink conducts heat generated by the at least one light emitting diode away from the at least one light emitting diode and out of the enclosure; and
- at least one electric component housed between the sidewalls of the heat sink.
10. A light fixture as in claim 9, wherein the set of fins comprises at least two individual fins that are parallel to one another, and wherein the set of fins is angled downward from the upper surface of the enclosure.
11. A light fixture as in claim 9, wherein the enclosure comprises a polycarbonate and the heat sink comprises metal.
12. A light fixture as in claim 9, wherein the light source assembly further comprises a thermal interface material coupled between the mounting panel and the at least one light emitting diode.
13. A light fixture as in claim 9, wherein the enclosure further comprises bottom portion coupled to the top portion.
14. A light fixture as in claim 13, wherein the bottom portion of the enclosure comprises a lens for refracting light emitted by the at least one light emitting diode.
15. A light fixture as in claim 9, wherein the light fixture is water-resistant.
16. A method of manufacturing a light fixture, the method comprising:
- providing an enclosure comprising a top portion and a bottom portion coupled to the top portion to define a cavity;
- defining an aperture in the top portion of the enclosure;
- providing a heat sink comprising at least one set of fins proximate a top of the heat sink and two opposing sidewalls extending downwardly from the at least one set of fins;
- positioning the heat sink within the enclosure such that the at least one set of fins are positioned exterior to the enclosure and at least a portion of the sidewalls are positioned within the cavity of the enclosure;
- coupling the heat sink to the enclosure; and
- coupling a light source assembly to at least one sidewall, wherein the light source assembly comprises a mounting panel and at least one light emitting diode.
17. A method of manufacturing a light fixture as in claim 16, further comprising coupling a gasket between the heat sink and the enclosure.
18. A method of manufacturing a light fixture as in claim 16, further comprising housing at least one electric component between the sidewalls of the heat sink.
19. A method of manufacturing a light fixture as in claim 16, further comprising coupling a side bracket to a sidewall of the pair of sidewalls; and
- coupling an additional electric component between the sidewall and the side bracket.
20. A method of manufacturing a light fixture as in claim 16, further comprising coupling a transition piece to an end of the heat sink and to the top portion of the enclosure.
Type: Application
Filed: May 6, 2011
Publication Date: Jan 12, 2012
Patent Grant number: 8613528
Inventors: Craig Eugene Marquardt (Covington, GA), Jie Chen (Snellville, GA), Seun Ilenbiluan (Conyers, GA), Jeffery Allen Watson (Covington, GA), Daniel Edward Sicking (Lawrenceville, GA), Aaron James Becker (Covington, GA), Mark Anthony Hand (Covington, GA)
Application Number: 13/102,767
International Classification: F21V 29/00 (20060101); H05K 13/00 (20060101);